The cathode current collector of a battery serves several functions. One of the functions is to conduct the flow of electrons between the active material of the electrode and the battery terminals. Cathode current collectors may also provide some support for the cathode active material. Cathode current collector materials must maintain chemical stability and mechanical integrity in corrosive electrolytes throughout cell life. However, this is often a problem, since the availability of materials capable of meeting such requirements is limited. Often battery operating conditions are such that corrosion of the current collector occurs.
Corrosion of the metal current collectors, particularly at the cathode (positive electrode), is a problem. A metal foil current collector, such as nickel, is electrochemically dissolved. This is a problem especially if very thin current collectors are used. Corrosion often leads to loss of contact, electronic isolation and, consequently, to poor battery performance.
Therefore, what is needed is a cell construction and method of operation which overcomes problems with corrosion in order to prevent degradation of cell performance.